12-12-2014, 09:08 AM
I wish I could get to the bottom of this question which keeps coming up and starting arguments. I personally believe that the solids could not be moving that far or else we would see all kinds of solids from the forest above whenever a hole was dug or a lava tube explored. We don't. Nevertheless all the evidence needs to fit and some of it seems contradictory. For example, septic tanks do get full and need to have solids pumped out so that argues that the solids don't just digest away to nothing. On the other hand my parents have lived in a house with a septic tank and leach field and have only had it serviced once in over 30 years. Pumping it is definitely not a regular thing or it would have failed already many times. The answer may be that for most of those 30 years it has been only them and sometimes myself. I think that there is a tremendous reduction in solids volume over time in both cesspools and septic tanks but septic tanks are stagnant pools of water while the intermittent filling and draining of cesspools pumps air throughout the active zone. Anaerobic reduction is much slower than aerobic even if they both get the same place eventually. In cases like that of my parents the rate of introduction of solids is so low that the anaerobic microbes keep pace. Since there are no rocks in poop it can reduce down to almost nothing given enough time. Still it is a common thing that septic tanks get full of solids while here in Hawaii cesspools don't.
For the record I think that there is a zone perhaps two or three times the dimensions of the cesspool, where all the solids get trapped and eventually degrade away to almost nothing at about the same ratio that wood gets burned down to ash, and that this is possible because the periodic flows of water pump air through this region. I don't think that poop is making it hundreds of feet in any recognizable form except in the case of lava tubes. Even in those cases I suspect that the water drains into cracks and the result from that point is identical to a cesspool. Not that I would want to explore those tubes on foot.
The issue of perched aquifers is similarly intriguing. I understand that the Honolulu Board of Water Supply makes great use of aquifers in the mountains that are far above sea level. I also understand that if I go to a well driller he will tell me to expect to drill down nearly to sea level to get water. I think that the difference is that the BWS has the resources to explore for these sites whereas the homeowner has to just get lucky.
For the record I think that there is a zone perhaps two or three times the dimensions of the cesspool, where all the solids get trapped and eventually degrade away to almost nothing at about the same ratio that wood gets burned down to ash, and that this is possible because the periodic flows of water pump air through this region. I don't think that poop is making it hundreds of feet in any recognizable form except in the case of lava tubes. Even in those cases I suspect that the water drains into cracks and the result from that point is identical to a cesspool. Not that I would want to explore those tubes on foot.
The issue of perched aquifers is similarly intriguing. I understand that the Honolulu Board of Water Supply makes great use of aquifers in the mountains that are far above sea level. I also understand that if I go to a well driller he will tell me to expect to drill down nearly to sea level to get water. I think that the difference is that the BWS has the resources to explore for these sites whereas the homeowner has to just get lucky.